diff --git a/sccp/SCCP_Tests.ttcn b/sccp/SCCP_Tests.ttcn
index ea2522a..e76e9ac 100644
--- a/sccp/SCCP_Tests.ttcn
+++ b/sccp/SCCP_Tests.ttcn
@@ -4,6 +4,8 @@
  *
  * Released under the terms of GNU General Public License, Version 2 or
  * (at your option) any later version.
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
  */
 
 module SCCP_Tests {